In anticipation of the Techonomy Detroit conference on September 12, we're profiling six Detroit tech startups that are driving the city’s re-emergence as a center of innovation.

Detroit has become notorious as a symbol of the decline of American manufacturing, but in recent years the city’s tech start-up scene has quietly started to attract attention and generate renewed optimism. Investors like Detroit Venture Partners have sought to rebuild the city through entrepreneurship, financing successful tech-focused efforts, including web, iOS, and Android applications from a company called Detroit Labs. Detroit is now home to an outpost of TechShop, the Silicon Valley innovation incubator where people of all skill levels can use industrial tools and equipment to build their own products. Meanwhile, entrepreneurship accelerator Bizdom offers seed funding to help grow tech-based local startups.

GreenLancer Energy connects freelance renewable energy engineers with companies and contractors looking for green expertise. Since 2011, GreenLancer’s clients have included the U.S. Department of Defense, Occidental Oil, General Motors, and the U.S. Armed Forces. I spoke with co-founder and CTO Patrick McCabe about freelancing renewable energy, the Midwest’s lack of green energy experts, and Detroit’s tech scene.

What was the genesis of GreenLancer?

We’d been doing web-based design for solar electricity for several years, and by web-based I mean we were working from our computers remotely on projects all over the country. We had come up with this systematic approach, so what we did was productize our engineering services and make them available e-retail style online. The whole inspiration was that we wanted to do engineering remotely for clients on all sides of the renewable energy industry.

Talk about some of the projects you’ve worked on.

We’ve been involved in big projects all over the country, mainly in solar. We’ve also done small-scale wind projects and lighting retrofits. We’ve done solar-thermal projects, and we’re doing EV [electric vehicle] charging stations right now—solar carports. We’ve done projects in six different countries and all over the US—I think it’s 25 different states now. We provide technical sales tools for project developers, and then we also do the hard-core engineering so that installers can get the necessary permits for the build out.

What does your client base look like?

It's typically prime contractors, meaning electrical contractors, roofing contractors, and general contractors. These are basically businesses that have the tools and the resources to do clean-tech projects, but don’t have the expertise. GreenLancer provides expertise so these clients can develop and install clean-tech projects.

Did you start GreenLancer with the intent to go national?

From our first foray into doing this web-based design, we realized that we had to diversify our market offerings, so we had to be national as opposed to local. We also knew we had to diversify the technology markets that we were in, so instead of just doing solar, we applied our engineering system to wind, geothermal, lighting retrofits, and EV charging stations. We set out with a national, scalable, kind of business model.

Are there particular regions with a more acute need for green energy expertise?